Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/16/18

Area Forecast Discussion
National Weather Service Amarillo TX
602 PM CDT Sun Jul 15 2018 .AVIATION... 00Z TAF Cycle Showers and thunderstorms will impact the three TAF sites through about 01Z to 04Z Monday with thunderstorm wind gusts up to 35 to 45 knots and some possible MVFR ceilings and visibilities. Otherwise, VFR conditions will prevail at the three TAF sites through 00Z Tuesday. Southeast to south and southwest winds mainly 5 to 15 knots except in and near any thunderstorms where variable winds sustained at 15 to 25 knots with the higher gusts can be expected. Schneider && .PREV DISCUSSION... /Issued 330 PM CDT Sun Jul 15 2018/ DISCUSSION... Short Term (This Afternoon and Tonight)... Mid-Upr level trough axis has drifted west through the day and this has helped improve moisture profiles and seems to have lifted the lid a bit as we are seeing much more convective development than this time yesterday. Much of the area is include in SCT POP cats for the remainder of the aftn into evening with highest coverage expected along SW to NE diagonal through middle of CWA and across the OK Panhandle. The HRRR and TTU WRF seem to have good handle on this now, but CAMs have been struggling to say the least. ML cape of 1000-2000 J/kg and SB cape of 2000-3000 J/kg and weak shear supports strong pulse storms. Very isolated severe wind gusts cause by microburst are possible given 1200-1600 J/kg downdraft capes noted in SPC meso analysis. That said, lighting and torrential downpours and localized flooding are likely the main threat with these slow movers. Expect lingering elevated storms beyond midnight as we have seen the last several days perhaps focused on central counties. In fact this is the first time CAMs (HRRR in this case) seem to even be trying to forecast these. Will maintain POP through the night as a result. NBM has been doing well on lows and looks good. MJG Long Term (Monday through Saturday)... Continued chances for convection will prevail across the Panhandles through Monday and Monday night. The forecast area will remain between one upper high over the Great Basin region and Four Corners region and the other upper high over the northwest Gulf states. The upper high over the northwest Gulf states expected to build back to the west and north across the Panhandles Tuesday. Convection chances Tuesday afternoon and Tuesday night should be confined mainly to the far northern portions of the forecast area, however confidence low. The upper high will build over the Panhandles mid to late week which will result in hot and dry conditions Wednesday through Friday and possibly into the upcoming weekend. A Heat Advisory may be likely over mainly the southern portions of the Texas Panhandles, especially the Palo Duro Canyon, Wednesday through Friday as max temps forecast to reach 105 to 108 degrees. A weak shortwave may possibly affect the far northern Panhandles Friday night which could result in isolated convection, but again, confidence low. Otherwise, the hot and dry conditions will prevail the end of the week through the upcoming weekend. Schneider && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 11/89
Area Forecast Discussion
National Weather Service State College PA
1101 PM EDT Sun Jul 15 2018 .SYNOPSIS... Very warm and humid weather will persist into Tuesday with a gradual increase in the chance for showers and thunderstorms until a cold front passes through late Monday night and Tuesday. Canadian high pressure will follow and bring a refreshing change back to much lower humidity and near to slightly below normal temperatures for the second half of next week. && .NEAR TERM /UNTIL 8 AM MONDAY MORNING/... No significant changes to gridded fields that highlight the overall fair and muggy conditions overnight. Previous Discussion... Upper level ridge cresting right over the region late tonight, coupled with a lack of any appreciable llvl moisture convergence means a partly cloudy and muggy night for the entire CWA. Min temps early Monday - ranging from the mid to upper 60s across the northern mountains and upper 60s to lower 70s elsewhere, will be 5-10F above normal for mid July. Aside from a lone shower over the NE corner of Sullivan County, the regional radar Dual-Pol scope was PPINE. Last few runs of the HRRR and RAP13 indicate little or no chc for additional showers overnight, and all of our POPs through 12Z are 10 percent or less. Patchy 1-2SM fog will form throughout the valleys considering the high sfc dewpoints and fairly narrow T/Td spread already. && .SHORT TERM /8 AM MONDAY MORNING THROUGH 6 PM MONDAY/... As the upper trough over OH/KY slides in Monday, it will aid storms to form, perhaps before noon in the west. WPC MRGL risk of excessive rain is drawn over the western part of the area Mon, and we will continue to mention heavy rain poss there. They should be moving a little from W-E, but still slowly. Another big worry is the Heat Index may get near 100 as well Mon. Have chatted with the neighboring offices and the consensus is that we will likely stay just under advy criteria - u90s. Nevertheless, it is going to be another hot and muggy one. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Cold front will move southeast through the Northwest mountains early Tuesday morning reaching Harrisburg by late afternoon and clearing the lower Susq valley by evening. High PWAT air, increasing deep layer shear (20-30 kt)and the cold front may lead to strong thunderstorms depending on the amount of sunshine. SPC has portion of Central PA in a marginal risk for severe. Drier air and building pressure behind the Cold Front Tuesday night into Wednesday helps clear things out and drop high temperatures Wednesday about 5 degrees over Tuesday but humidity will also be notably more comfortable. High pressure over PA Wednesday night will slide east off the coast. Flow aloft will shift from northwest to southwest and surface winds will turn southeast. GFS hints at a marine layer moving into lower Susq Thursday night and a return of higher dew points may bring some patchy morning fog. Next system approaches late Friday with a low center trying to form on the coastal front off the Carolinas which moves north to just of the Delmarva and the main parent low center back over the Great Lake Region to bring more unsettled weather for the weekend with the chance of scattered showers and thunderstorms. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Storms remain isolated and most airfield will be rain free this evening. Visibility should be VFR unless you happen to get right under a cell. But, after dark, the stabilization and light wind will likely lead to fog formation, esp in places which received heavy rain today, and in the valleys of the north where it may clear out completely. A minor shortwave trough moves in from the west on Monday and will flare storms up again, perhaps in the morning over the west. But, the rest of the area will wait until at least noon to see things flare up. Will just mention some SHRA in the western terminals aft 14Z, and leave it out of others. More widespread activity on Tuesday, ahead of a cold front. Improving conditions after that, as drier air works into the area. .Outlook... Tue...CFROPA with numerous TSRA and lowered vis/cigs likely. Wed-Fri...AM valley fog N, otherwise, no sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Dangelo/Lambert LONG TERM...Watson AVIATION...Dangelo/Gartner
Area Forecast Discussion
National Weather Service Quad Cities IA IL
951 PM CDT Sun Jul 15 2018 .UPDATE... Issued at 941 PM CDT Sun Jul 15 2018 Area radars show a thin line of convection has developed since 01z from northeast Iowa into central Iowa, or roughly from northeast of KDEH, to KIFA, to near KDSM. Convection appears to be developing mainly due to the strong theta e gradient in the area associated with what appears to be a weak trof/front. RAP trends slowly moves this feature east overnight through the area. However, the RAP does show weakening convergence over the northwest quarter of the area through 07z before strengthening it again in the hours prior to sunrise. Thus will update the forecast to reflect the potential for a narrow band of mainly isolated to scattered showers moving through the area late tonight. One cannot rule out an isolated rumble of thunder. An updated forecast should be available in about 5 minutes or so. && .SYNOPSIS... Issued at 220 PM CDT Sun Jul 15 2018 Low clouds continued to decrease in coverage during the early afternoon hours. Scattered showers developed across parts of eastern Iowa, in an environment favorable for brief funnel clouds, which were reported in Benton and Johnson Counties. The cloud cover kept early afternoon temperatures down in the upper 70s to mid 80s, but heat index values in the mid 80s to low 90s were common. && .SHORT TERM...(This Evening through Monday) ISSUED AT 220 PM CDT Sun Jul 15 2018 The main forecast issue in the short term period is the coverage of showers and isolated thunderstorms this afternoon and tonight, as well as the potential for additional funnel clouds. Funnel reports have coincided with developing showers across eastern Iowa, from Vinton and Cedar Rapids, through Mt. Pleasant into far northeast Missouri. The axis of favorable surface convergence and enhanced stretching potential is expected to move little through the late afternoon, so this area should continue to be the prime location for additional funnel clouds. Will continue to cover with special weather statements. A drier airmass today means that rainfall should not be excessive, and no severe weather is expected. CAMS are in general agreement in gradually shifting isolated showers and storms eastward along a weak front this evening and overnight. Expect another muggy night with lows in the upper 60s/low 70s. The front will exit the area to the east Monday morning, and the far southeast fringe may have some lingering showers in the morning. Drier air will move into the northwest counties, while higher dewpoints linger southeast with afternoon heat index values in the low 90s. .LONG TERM...(Monday Night through Sunday) ISSUED AT 220 PM CDT Sun Jul 15 2018 Monday through Wednesday, The upper air pattern aloft will shift to the northwest as a long wave ridge builds over the inter-mountain west and a deep trough develops over the eastern CONUS. This flow will usher in drier air as high pressure builds into the upper midwest from Canada. Dry and seasonably mild conditions are on tap for Tuesday and Wednesday with high temperatures ranging in the upper 70s to low 80s. On Tuesday and Wednesday night, clear skies, light winds, and dewpoints in the upper 50s to around 60 will produce temperatures in the lower 60s over most of the region. Lows in the upper 50s are possible in locations across the north. Thursday and Friday, The blended models prog a strong upper level shortwave to push through the western ridge. This wave is expected to dive southeast over the upper Mississippi Valley, eventually closing off over the Great Lakes bringing a chance of storms. High temperatures both days will be in the upper 70s to lower 80s. Saturday and Sunday, Skies will be mainly dry on Saturday as high pressure builds into the area out of Canada. However on Sunday, a cyclonic flow aloft around the back side of the closed low over the Great Lakes, will bring a chance of storms. Temperatures will be near to below normal with highs in the 80s. && .AVIATION...(For the 00Z TAFS through 00Z Monday Evening) ISSUED AT 634 PM CDT Sun Jul 15 2018 Diurnal convection and clouds will dissipate through 01z/16 leaving VFR conditions through 06z/16. After 06z/16 MVFR/VFR conditions with patchy fog are expected. The fog may get locally thicker and produce patchy IFR condition. After 14z/16 any IFR/MVFR conditions will improve to VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...RP Kinney SHORT TERM...RP Kinney LONG TERM...Kuhl AVIATION...08
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
331 PM MDT Sun Jul 15 2018 .SYNOPSIS... An active monsoon pattern will continue to produce scattered showers and thunderstorms this afternoon and evening, with another round expected on Monday. However, drier air will work into the region on Tuesday. After Tuesday, weather will become more June- like with isolated thunderstorms mainly in the Sacramento Mountains and Gila Region, and high temperatures increasing into the lower-100s in the lowlands. && .DISCUSSION... Larger scale pattern has evolved as expected, with our split subtropical ridge still in place (though both the western and eastern centers are weakening), with a weak trough in between extending from the Texas Panhandle into south-central New Mexico. The inverted trough discussed yesterday has wound itself up over south Texas. While it is most readily apparent at 200 mb, there is a weak 500 mb reflection as well. An outflow boundary from Arizona that pushed into SW New Mexico around Midday has had disappointing results in terms of generating new convection in SW New Mexico. RAP analysis has a relative minimum of CAPE over Luna/Dona Ana Counties, but despite this, cumulus congestus is "clumping up" in southern Dona Ana and western El Paso counties. Thick anvil blowoff from earlier convection in the Sacramento Mountains is spreading into the El Paso and Las Cruces areas from the northeast. Despite this, outflow has managed to generate new convection from Orogrande eastward into the Otero Mesa, though this may be aided by the weak trough hanging back across the eastern half of New Mexico. It`s a tough call, but El Paso still has a fair shot of getting decent storms this afternoon/evening. We`ll hang on to this same pattern again tomorrow, but the NAM/GFS now suggest eastern parts of the CWA will be clipped by a weak vort lobe associated with the approaching inverted trough. Several of the HREF members pick up on this too, showing a more organized band of thunderstorms moving up from the SE during the early afternoon. But for the most part, this inverted trough will mainly benefit areas south of the border with precip. Drier continental air aloft will move in behind it, drying out most of the area beginning Tuesday and lasting through the week. There will be enough residual moisture around for isolated storms in the higher terrain of the Gila and Sacramentos, and maybe a lowland stray, but activity will be much diminished. Temperatures will slowly climb through the week, likely reaching the century mark in the lowlands (including ELP) Wed or Thu. Recycled moisture will try to work around from the north late in the week, but warm mid-level temperatures will limit instability. && .AVIATION...Valid 16/00-17/00Z. Moisture remains plentiful with scattered thunderstorms and showers thru the period for all terminals. Best chances for convection will be between 00Z and 06Z and again after 18Z. During these periods look for SCT -TSRA AND +TSRA/WIND VRB15G35KT with CIGS 040-060. Occasional MVFR ceilings and LCL VSBY 3-5SM AGL will also be possible with any heavier storms passing directly over individual terminals. Otherwise expect SCT060-080 SCT-BKN120 BKN-OVC250 to prevail outside of convective episodes. && .FIRE WEATHER... Abundant moisture is expected to remain in place through Monday with decent chances for wetting precipitation for all areas. A drying trend will begin on Tuesday as deeper moisture is pulled westward into Arizona and high pressure builds over the state. Circulation around the high will import drier air into the region and reduce chances for showers and thunderstorms to a more isolated and mainly mountain based occurrence for the remainder of the week. Minimum relative humidity values will drop to the upper teens by the middle of the week and continue into next weekend. Vent rates will continue be in the good to very good range. Non-thunderstorm induced easterly winds will remain light and generally under 10 mph. Wind gusts from thunderstorms will have speeds of 40 to 50 mph. && .PRELIMINARY POINT TEMPS/POPS... El Paso 73 91 75 95 / 50 50 20 0 Sierra Blanca 69 89 69 93 / 40 60 20 0 Las Cruces 69 89 69 94 / 50 40 40 0 Alamogordo 69 90 70 93 / 40 40 20 0 Cloudcroft 53 68 52 73 / 40 70 40 10 Truth or Consequences 70 89 71 91 / 40 30 40 0 Silver City 62 81 65 88 / 50 60 50 30 Deming 67 88 67 93 / 40 40 30 0 Lordsburg 66 87 69 93 / 50 30 50 10 West El Paso Metro 72 89 72 93 / 60 50 30 0 Dell City 69 94 68 96 / 40 60 20 0 Fort Hancock 71 92 72 96 / 40 60 20 0 Loma Linda 66 87 67 91 / 60 60 20 0 Fabens 68 90 68 94 / 50 50 20 0 Santa Teresa 71 90 71 94 / 60 50 30 0 White Sands HQ 71 89 72 93 / 60 50 30 0 Jornada Range 67 90 68 94 / 60 40 30 0 Hatch 68 90 69 94 / 40 40 40 0 Columbus 69 88 69 94 / 40 30 30 0 Orogrande 72 91 72 94 / 50 50 20 0 Mayhill 57 77 57 82 / 40 60 40 10 Mescalero 57 77 57 84 / 40 70 40 10 Timberon 56 76 55 79 / 40 70 40 10 Winston 57 81 57 85 / 60 50 50 30 Hillsboro 64 87 64 91 / 50 50 40 20 Spaceport 66 89 66 92 / 40 40 30 0 Lake Roberts 53 80 52 86 / 50 60 60 30 Hurley 61 83 62 87 / 50 50 50 20 Cliff 58 86 61 91 / 40 50 60 20 Mule Creek 62 83 65 90 / 40 60 60 30 Faywood 63 85 63 89 / 40 50 40 20 Animas 67 88 67 94 / 50 40 60 0 Hachita 67 87 67 93 / 50 30 40 0 Antelope Wells 67 86 66 91 / 50 50 60 10 Cloverdale 64 82 63 90 / 50 60 60 20 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25-Hardiman / 04-Lundeen
Area Forecast Discussion
National Weather Service Lincoln IL
903 PM CDT Sun Jul 15 2018 .UPDATE... Issued at 902 PM CDT Sun Jul 15 2018 Two areas of convection are still in progress at the mid-evening point, in Knox county and south of I-70. High resolution guidance is showing that those showers/storms will gradually dissipate, with a spotty shower or storm still possible the rest of the night in our far SE and far NW. Otherwise, the majority of central and SE IL should remain dry the rest of the night. Surface dewpoints in the low 70s overnight will set the stage for the potential development of fog, some locally dense, as low temps drop into the low 70s. A stratus layer could also develop in some southern counties, per the latest HRRR. Have continued with the increasing cloud trend after 3 am tonight, with patchy fog in all areas. Precip chances tomorrow look to be mainly in the eastern half of the CWA, as the cold front passes through the area between 9 am and 2 pm. No severe storms are expected, but locally heavy rainfall and gusty winds will be possible. Outside of any storms, winds will generally be light and variable overnight, and light southerly ahead of the front tomorrow. A wind shift to NW will follow the front, as less humid air begins to make an entrance later tomorrow and tomorrow night. Updates tonight were done to the weather/PoP grids. The remainder of the forecast looked on track. Updated info should already be available. && .SHORT TERM...(This evening through Monday) ISSUED AT 309 PM CDT Sun Jul 15 2018 Majority of the precip was shunted off to the south throughout the day, with plenty of cu developing early across Central IL. Enough clouds developed across the region to limit some of the heating. Satellite imagery also shows a significant swath of dry air, also evident in the 12z ILX sounding, spread across the region slowly progressing into the Ohio River Valley. However, the dry air is not mixing all the way down to the surface through the clouds. Dewpoints this evening are still in the 70s. And although there are a few showers scattered about Central IL this afternoon, the clouds are diminishing in other locations, hinting to a bit of clearing going into the overnight hours. With the dewpoints that high, and a potential partly/mostly clear night, patchy fog concerns come into question. Although a frontal boundary is on approach, it is moving into a very weak pressure gradient, and the winds are expected to be light and variable if not calm. So...along with low pops in the overnight, increasing to morning... have gone ahead and put the patchy fog in as well. The struggle between some isolated showers and patchy fog with any brief clearing will continue through the overnight hours into the early morning. Winds should start coming around to more northwesterly in the early morning, but the dry air lags behind the boundary considerably. Tomorrow will still be rather warm and muggy as the precip associated with the frontal passage slowly works across the area. Storms tomorrow will likely be accompanied by some fairly gusty winds considering the dry air available aloft. .LONG TERM...(Monday night through Sunday) ISSUED AT 309 PM CDT Sun Jul 15 2018 Once the front moves through, the temps cool into the mid 80s into the middle of the week, with drier air making it feel considerably more comfortable. Thursday, the next system deepens enough aloft to pull even cooler air into the mid levels from the northeast, potentially setting up some decent lapse rates for showers and thunderstorms for Thursday night/Friday...and offer some below normal temperatures going into the weekend. And in the last 24 hours, the models have corrected that dry weekend in more northwesterly flow. Currently the GFS and the ECMWF are cutting off that upper low in the Ohio River Valley, leaving cyclonic flow in place and slowly drifting over the region for a cloudy and periodically rainy weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 705 PM CDT Sun Jul 15 2018 A residual surface boundary in east-central IL has been a focus for a few showers/storms late this afternoon, between CMI and DEC. The CMI complex has dissipated to light showers, while the southern end of the convergence line has activated just NE of DEC. HRRR output is showing the convection may to linger in EC IL this evening, but coverage should remain isolated. Lingering boundary layer moisture may cause more IFR clouds later tonight, esp near DEC, BMI, and CMI, per the HRRR. Have kept the tempos for IFR fog later tonight, but some of the fog could become dense. Will watch trends in the high res models to see if LIFR or VLIFR conditions need to be included in a tempo for late tonight. Any lingering MVFR clouds early this TAF period should dissipate with loss of turbulent mixing, so VFR conditions should prevail until after midnight when fog begins to form. Winds will be variable across the area, under the weak pressure gradient, and eventually prevail out of the NW after the cold front moves through tomorrow. Spotty convection will accompany the front, but did not include storm chances at any TAF site during the day tomorrow yet. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...HJS LONG TERM...HJS AVIATION...Shimon
National Weather Service Jackson KY
1045 PM EDT Sun Jul 15 2018 .UPDATE... Issued at 1045 PM EDT SUN JUL 15 2018 Updated zones to remove last of the thunder earlier and to remove showers for most areas through the night as shower activity has diminished to only a few remote showers in Harlan county. This activity should follow suit and diminish as there will be little forcing to sustain activity overnight. Latest hi-res model guidance suggest rain chances tomorrow may hold off until at least the afternoon hours, so did pull back rain chances a bit during the morning hours. UPDATE Issued at 858 PM EDT SUN JUL 15 2018 A few widely isolated showers and storms continue to impact areas of east Kentucky. However, the trend has definitely been for less activity as we have moved past sunset. With instability limited overnight, will pull the mention of thunder from the overnight portion of the forecast. Will maintain isolated showers overnight, but most locations will stay dry through the overnight hours. Withe expected cloud cover overnight, fog will be more limited tonight, so will not include in the valleys. && .SHORT TERM...(This evening through Monday night) Issued at 450 PM EDT SUN JUL 15 2018 19z sfc analysis shows low pressure off to the northwest along with a frontal boundary. This front`s slow approach (along with some energy aloft) is helping to spread showers and thunderstorms across Kentucky this afternoon with isolated to scattered coverage over the JKL CWA. Any of the stronger storms would contain heavy downpours and plenty of cloud to ground lightning. The convection is providing some relief from the warm temperatures this afternoon with readings down in the mid 70s in the rain and in the mid to upper 80s elsewhere. Dewpoints, meanwhile, remain elevated in the low to mid 70s while winds, outside of the storms are running from the south to southwest at 10 kts or less - though blowing at up to 30 kts with any thunderstorm. The models are in good agreement aloft with the start of a significant pattern change through the short term portion of the forecast. They all depict the retreat of the ridge that has dominated our weather for much of the summer so far. This occurs as a weakening trough passes by to the north and its energy shifts through Kentucky tonight into Monday. A larger trough will then move just into the northern Great Lakes sending more height falls into the Ohio Valley by 12z Tuesday. Given the model agreement will again favor a general blend though with emphasis on the higher resolution CAMs and NAM12 for weather details. Sensible weather will feature evening showers and storms with a diurnally typical downturn after sunset, though the latest HRRR seems to suggest the convection lasting deep into the night - but still rather scattered. Due to the clouds and convection around will limit the ridge to valley temperature differences tonight and Monday night. Likewise have kept the fog mainly in the river valleys, though places that manage to clear out after seeing rain will also have a shot at some fog in the middle of the night. For Monday, the front settles closer and with high PW air in place expect better coverage of the convection along with heavy rains from individual cells that could become excessive for any location that receives training storms. Have highlighted this threat in the HWO - and it corresponds with a marginal outlook for excessive rains from WPC. Temperatures will still be able to get quite warm on Monday, but with the clouds and rains around readings should top out about a category lower than today most places - though dewpoints remain quite high. Again used the CONSShort and ShortBlend as the starting point for the grids with only small adjustments to temperatures based on terrain tonight and Monday night. As for PoP, basically kept the blended solution through the short term period while smoothing out some of the gradients due to uncertainty in this moist and unstable environment. .LONG TERM...(Tuesday through Sunday) Issued at 340 PM EDT SUN JUL 15 2018 As the period starts, a southeastward moving cold front will be over or just northwest of the JKL forecast area, supported by an upper level trough moving east southeast over the Great Lakes. Warm and humid air ahead of the front should support at least scattered showers and thunderstorms. There is some variation in frontal timing in the models, with an average suggesting the front will be passed by Tuesday evening. Behind the cold front, surface high pressure will move from the Great Lakes across New England Tuesday night through Thursday night and bring us a return of dry weather. The air mass which arrives looks like it will be dry enough to allow the colder valleys to dip into the 50s for lows. With the high moving away to the east, a return flow of warmer and more humid air will occur to end the week. At the same time, another more significant upper trough is forecast to develop and move southeast over the eastern CONUS. This results in another cold front and the potential for more showers and thunderstorms. At this long time range, the models differ in the details for the amplitude of the upper trough and timing of the surface front. However, both the ECMWF and GFS are consistent with the same general pattern, lending confidence for the scenario. The persistence and strength of the slow moving upper trough supports an extended potential for precip, probably even after cold fropa. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) ISSUED AT 858 PM EDT SUN JUL 15 2018 Generally speaking most places should see VFR conditions through Monday morning. Some fog from the rainfall this evening will be possible before it lifts in a few hours. More showers and storms will develop Monday afternoon and evening associated with a cold front moving in from the northwest. Thunderstorms will cause some temporary reductions in visibilities and ceilings during the afternoon hours and will maintain a VCTS in the TAFS. Winds will continue to be light through the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...GREIF LONG TERM...HAL AVIATION...KAS
Area Forecast Discussion
National Weather Service Memphis TN
917 PM CDT Sun Jul 15 2018 .DISCUSSION...A combination of a Mesoscale Convective Vortex (MCV) and ample instability was responsible for the scattered to numerous showers and thunderstorms earlier during the afternoon/early evening hours. Showers and thunderstorm coverage has diminished substantially over the past hour across the Mid- South. Short term models including many Convective Allowing Model (CAM) solutions are still running well behind on the evolution of the earlier convection. Consequently, I`m leaning towards the latest HRRR at this point for the remainder of the night. Will make some adjustments to rain chances for the remainder of the night and to adjust any other elements as needed. CJC && .PREV DISCUSSION... /issued 630 PM CDT Sun Jul 15 2018/ UPDATE... See the 00z aviation discussion. PREV DISCUSSION... /issued 213 PM CDT Sun Jul 15 2018/ DISCUSSION... Soaring heat is in full swing across the Midsouth this hour...with portions of northwest Tennessee reaching criteria then cooling off quickly from line of storms. Reluctant to cancel the advisory though as plenty of afternoon is left for them to rebound back. Out in the western counties untouched by thicker clouds and/or storms..a few locations have topped 110F. With regards to convection a few cells have reached near severe limits off radar...but with no reports of damage or hail. Rainfall from Lake to Henry counties has been a welcomed 1 to 2.5 inches. For tonight through Tuesday...short term CAM`s suggesting multiple rounds of convection over the next 24 to 36 hours. Current and overnight activity influenced by the passing MCV in the Lower Ohio Valley...and then tomorrow and Tuesday influenced by a descending cold front seen in the Plains. Both features likely to bring a threat for a few strong or severe storms as dewpoints remain rich over the region...75F+. Concerns for additional heat related products will now become very questionable as extensive cloud cover from activity will play a big role in temperatures. Highs appear to reach 90 to 94F tomorrow...which could allow an hour or two of 105F heat indices along and west of the Mississippi River...but widespread values seen today aren`t favored. With that in mind will allow the current advisory to expire at 9pm tonight...with the night crew making a final call on whether areas will need one tomorrow. Tuesday will be FROPA day...fingers crossed...with slightly better coverage of storms over the southern two-thirds of the CWA. Heat indices are forecast to stay below 105F area wide. Wednesday and frontal airmass will provide some relief...with highs expected to be at seasonal normals or a couple degrees below. Dewpoints will fall a good five degrees as well...ranging from 67F to 72F. Heat indices will generally be in the 95-100F range. Convection coverage will become more isolated and mainly during the afternoon hours across the western counties Wednesday...overspreading the remaining Midsouth counties on Thursday. Lows will range from the upper 60`s to low 70`s...cooler than what has been seen at MEM for over two weeks. Next weekend...Rain chances will ramp back up in the long-range as both the Euro and GFS show an increase flow from the northwest. In fact, 500mb wind speeds could reach 50kts over the far northern counties...a late May and June scenario. Coupled with dewpoints near 70F...passing shortwaves could generate better storm organization. High and low temperatures this period will stay close to normal...generally low 90s and low to mid 70s. Afternoon heat indices for now remaining 95-102 degrees. JAB && .AVIATION... /00z TAFs/ Scattered convection will continue much of the evening but should gradually diminish in coverage. Maintained VCTS at all terminals for the next several hours. VFR conditions anticipated outside of convection in most areas, although patchy fog is possible at KMKL. Expect another round of scattered showers and thunderstorms Monday afternoon. The best chance for thunderstorms looks to be along/south of I-40. Johnson && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Nashville TN
924 PM CDT Sun Jul 15 2018 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Fairly quiet evening so far across Middle Tennessee as most of the convection has either died off or remained well west of the area. Current thinking is that this trend will likely continue overnight into the morning hours before another round of thunderstorms develops Monday mid day/afternoon. Even though confidence in the HRRR and the other short range models are well below low normal, do not see anything upstream that would spark thunderstorms like what we saw this time last night. So with that said, lowered POPs for overnight but will continue watching area radars for any hint of something that might produce a spark for convection. Otherwise, current temperatures are already in the low to mid 70s so only adjusted based on current trends. && .AVIATION... 00Z TAF DISCUSSION. Convection has decreased across the area this evening so expect VFR Conditions to continue until BR develops bringing MVFR visibilities to KCKV, KCSV, and KMQY between 08Z-13Z. Another round of convection can be expected some time after 12Z although pinpointing the timing will continue to be the main challenge. So included VCTS after 18Z for TAF terminals until confidence in development and timing increases. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Hurley AVIATION........Hurley
Area Forecast Discussion
National Weather Service Blacksburg VA
1114 PM EDT Sun Jul 15 2018 .SYNOPSIS... High pressure along the Mid-Atlantic coast will move east out into the Atlantic ocean tonight into Monday. A cold front Will approach our region Monday and move through Tuesday. && .NEAR TERM /THROUGH MONDAY/... As of 1110 PM EDT Sunday... Convection continues to weaken and diminish over our forecast area. Exception is in the NC High Country where mesoanalysis shows deeper moisture convergence along the NC/TN border, all the while a weak upper vort moves southeast from the Cumberland Plateau toward the southern Appalachians. Should still see showers fade after midnight, though will keep at least isolated threat in for a few more hours in the mountains. Plenty of mid and high clouds around so kept skies cloudier. This may limit fog formation as well, except in some of the deeper valleys in the mountains, and rainier spots from earlier. Previous discussion from early evening... Overall main area of convection still resides along the Alleghanys south into the NC/TN mountains ahead of weak vort. Best SBCAPE also resides here, however, seeing weakening trends as we head toward sunset. Will allow for pops to lower through this evening in the west. Otherwise expect some fog to form late tonight where it rained and where less cloud cover resides. Previous discussion from early afternoon... An upper level disturbance, weak shortwave trough will move east across our region this afternoon into tonight. The associated vertical motion combining with the increasing instability and moisture around the western periphery of the coastal high pressure is producing scattered showers and thunderstorms this afternoon. SPC Mesoscale analysis at 18z showed that CAPEs have climb to 1 to 3k j/kg and lis are minus 1 to minus 3 in western portions of forecast area. Mesoscale models like the HRRR and HighresW-arw are placing the greatest coverage generally west of the Blue Ridge. Some of the storm may try to drift east into the foothill this evening as hinted at by NAM and ECMWF. In any case, Scattered showers and thunderstorms will diminish and dissipate this evening into tonight with the loss of solar heating. Areas of low clouds and fog are expected tonight into Monday morning. Under variable cloudiness, low temperatures tonight will range from the lower 60s in the west to the lower 70s in the east. Several upper level disturbances traverses over our area Monday. The southwest to west flow will combine with rich moisture and instability to create scattered showers and thunderstorms especially during the afternoon and evening hours. The best opportunity for thunderstorms will occur in the mountains. With PWATS climbing to around 2 inches, some of the thunderstorms have the potential to produce locally heavy rains. high temperatures on Monday will vary from the mid 70s in the mountains to round 90 degrees in the piedmont. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... As of 240 PM EDT Sunday... An weak upper level trough will pivot over the region ahead of a cold front Monday night. A short wave associated with this trough will keep convection ongoing overnight, but areal coverage of storms will wane with lose of heating. Convection Monday afternoon and night will help remove instabilities across the mountains and therefore limit the potential for strong to severe storms Tuesday as a cold front tracks over the region. Tuesday morning, the cold front will move across the mountains, possibly making it to the Blue Ridge by noon. In the afternoon, diurnal heating along with a lee trough will generate a line of thunderstorms east of the Blue Ridge. The surface front is then expected to jump to the lee trough through the afternoon, continuing to track east during the evening. Models have this lee trough somewhere between HWY 29 and I-85. It is this area where strong to severe storms are likely Tuesday afternoon and evening. Even though the area has been in a dry spell for a week, some longer, with creeks and streams running well below normal, flash flooding is still a possibility. With a deep warm layer and PWAT values well above normal, slow moving strong thunderstorms could produce localized flash flooding. The mountains are susceptible to flooding Monday afternoon and evening, while the foothills and piedmont will see the threat Tuesday afternoon and evening. The front will be east of I-85 by midnight, however the dewpoint/Theta-E front lags behind. A few light showers may persist across northern North Carolina in the evening, but drier air and clearing skies will works it way south by sunrise Wednesday. There will be a noticable drop in humidities Wednesday, however, dry air and abundant sunshine will keep temperatures warm and near normal. The cooler air will arrive Wednesday night. Morning clouds and showers will keep mountains temperatures at or slightly below normal on Tuesday. Temperatures will range from the mid 70s to mid 80s. Temperatures will be at or above normal for the foothills and piedmont counties Tuesday. Temperatures will run from the upper 80s to lower 90s. Following the passing of the cold front, temperatures Wednesday will fall short of normal by 3F-6F. Highs will range in the 70s west to 80s east. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 240 PM EDT Sunday... Dry high pressure will move over New England and wedge south into Georgia Thursday into Friday. A disturbance will track along the eastern edge of the wedge (Southeastern states) Friday then off the North Carolina coast Friday night. At this time, this disturbance is far enough away to not bring any rain to the area. Over the Great Lakes, a closed low is expected to form. Short waves tracking around this low may bring showers and thunderstorms to the mountains Friday and to the entire forecast area next weekend. Forecast confidence is high through Saturday as both the GFS and ECM are in agreement. Models separate on Sunday to where the upper low will track. The GFS moves the low eastward towards Toronto while the ECM tracks it south into Indiana. Both scenarios will bring showers and thunderstorms into the region. Temperatures through the period will be near normal. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... As of 710 PM EDT Sunday... VFR conditions this evening with isolated/scattered MVFR cigs/vsbys with showers in the mountains and near ROA. Showers diminish overnight and will give way to some MVFR to IFR fog in the mountains. MVFR/IFR Showers and thunderstorms should become more widespread in the mountains especially mountains by Monday afternoon. Medium confidence in ceilings, visibilities and winds during the taf period. Extended Aviation... Scattered Showers and storms are expected across the region on Tuesday ahead of an approaching cold front. However confidence is too low to pinpoint where the showers and thunderstorms may occur. Also likely to see late night/early morning patchy fog result in localized sub-VFR in the valleys and where any earlier rainfall occurred each day through Tuesday. Conditions will dry out Wednesday, then moisture will return from the south Thursday. Scattered storms are expected in the west on Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK NEAR TERM...KK/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...KK/WP
Area Forecast Discussion
National Weather Service Shreveport LA
1104 PM CDT Sun Jul 15 2018 .AVIATION... Scattered convection well north of our airspace should remain to our north through the overnight hours. Thin cirrus noted on latest IR Imagery will continue to spread slowly westward through the overnight hours, otherwise VFR conditions should prevail tonight through much of the day on Monday. Did add VCTS to the TXK/ELD terminals as the HRRR is now painting some widely scattered convection north of the I-20 Corridor late on Monday. Otherwise, a growing cu field will prevail through the daytime hours on Monday. Light south winds overnight will become southwest near 10kts or less for Monday. 13 && .PREV DISCUSSION... /issued 934 PM CDT Sun Jul 15 2018/ UPDATE... Still watching some scattered convection just north of our region this evening. Short term progs not handling this weakness aloft very well so for the update, have added slight chance pops across our extreme northern zones. There should be a decreasing trend with this activity as we go through the night concerning coverage and intensity however. Concerning temps, raised temps a degree or two along the I-20 Corridor of NE TX to mimic overnight lows last night. Shaved temps just a degree or so across our SE most zones. Thin cirrus was located across our eastern half so made this change in the sky grids as well. All other grids are in good shape so no additional changes were necessary. Update out shortly...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 78 98 78 100 / 10 10 10 20 MLU 77 96 77 95 / 10 10 20 50 DEQ 74 94 73 98 / 10 30 20 30 TXK 77 95 76 98 / 10 20 20 30 ELD 77 95 75 96 / 10 20 30 40 TYR 78 96 76 100 / 10 10 10 10 GGG 77 97 76 101 / 10 10 10 10 LFK 75 96 75 99 / 10 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 13/13
Area Forecast Discussion
National Weather Service Great Falls MT
901 PM MDT Sun Jul 15 2018 .UPDATE... Most of forecast through daybreak tomorrow remains valid. Increased cloud cover over much of the CWA, especially south of the Hi-Line, given latest observed trends and 00Z/Mon HRRR guidance, which matched reality best. Also increased POPs and adjusted QPF accordingly over far-southwest MT. Here, a few showers and thunderstorms remain possible through daybreak Monday due to an approaching disturbance`s warm conveyor belt undergoing weak isentropic lift amidst appreciable moisture and instability. - Jaszka && .SYNOPSIS... An upper level ridge of high pressure will slowly build over the northern Rockies over the next few days. As a result, expect warmer temperatures to gradually move into the region. Afternoon highs are likely to range from the mid 80s to mid 90s across the entire region through the entire week. Additionally, weak upper level disturbances will move through Southwest MT, producing scattered showers and thunderstorms, mainly Monday afternoon through Tuesday. && .AVIATION... Updated 2307Z. Mainly VFR and westerly flow aloft expected next 30-hours as a high pressure ridge builds gradually over the area. However, a disturbance aloft centered offshore far-northern CA at this time moves northeastward to central ID by 06Z/Tue. Accordingly, isolated showers and thunderstorms are expected over/near the higher terrain of southwest and central MT between 16Z/Mon and 06Z/Tue, with the best potential for this activity spanning Mon afternoon and evening. Erratic surface wind gusts of 30-50 knots and brief MVFR are possible in/near any shower or storm. - Jaszka && .PREV DISCUSSION... /ISSUED 507 PM MDT Sun Jul 15 2018/ Today through Tuesday...No significant changes to the current forecast. An isolated thunderstorm is possible towards daybreak near the MT/ID border in Southwest MT otherwise an upper level disturbance will move into Southwest MT on Monday afternoon/evening. This disturbance will likely produce some scattered thunderstorms. A strong storm is possible, but coverage of the stronger storms looks quite low at this time. A few storms continue on Tuesday, but mainly over the eastern portions of the region. Expect above normal temperatures through the period. For Tuesday night through Sunday...overall a very warm period is expected. Afternoon temperatures could slowly fall back into the upper 80s by next weekend, but any cooling effects will be minimal. The chances for showers/storms looks very low at this time over the later portions of next week, thus pops are generally less than 10 percent for most areas. Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 55 91 60 91 / 0 0 0 10 CTB 50 90 53 92 / 10 0 0 10 HLN 57 87 59 89 / 0 10 10 20 BZN 54 83 56 84 / 0 20 20 40 WEY 49 74 45 76 / 20 30 30 30 DLN 55 82 53 83 / 10 20 30 20 HVR 53 92 60 94 / 0 0 0 20 LWT 55 84 58 83 / 0 0 10 40 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tulsa OK
847 PM CDT Sun Jul 15 2018 ...UPDATE... .DISCUSSION... Main concern is the potential for thunderstorm redevelopment late tonight and into early Monday morning, mainly across northeast Oklahoma and possibly northwest Arkansas. The latest mesoanalysis shows a well defined instability axis stretching roughly west to east across northeast Oklahoma into west central Arkansas, with multiple outflow boundaries from the afternoon and early evening convection also in the same area. This evidence, along with the last couple of HRRR runs, support the potential for additional development later tonight as another weak disturbance moves through the region. Only a few changes have been made to the thunderstorm chances through tomorrow morning, as the inherited forecast was already pointing toward this solution. The main change was to extend the axis of higher thunderstorm chances farther west, to the edge of the forecast area. No other major changes were made to the going forecast. Updates already out. && .PREV DISCUSSION... /Issued 637 PM CDT Sun Jul 15 2018/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Much of the convection that developed this afternoon has since dissipated across ern OK and nwrn AR. However, numerous outflow boundaries remain across the area, including one that is moving south from convection in sern KS, and several across far ern OK and nwrn AR. Mesoanalyses indicate that CIN has increased across nern OK ahead of the KS outflow boundary but remainder of area remains unstable and uncapped. Additional development possible this evening across nwrn AR, so included VCTS for a few hours those sites. Not as confident as last night in where and if overnight convection will redevelop, so no mention of TSRA overnight. Scattered thunderstorms likely to redevelop Monday afternoon and carried PROB30 groups all sites with that expectation. VFR conditions all sites through the forecast period outside of TSRA. PREV DISCUSSION... /Issued 312 PM CDT Sun Jul 15 2018/ DISCUSSION... Convective potential over the next several days will be the main forecast concern. The heat will be another concern thru tomorrow, with a break expected for a day or two. More excessive heat is expected toward the latter part of the week. A weak upper trough axis has become more east-west aligned today, stretching from Illinois to northwest Oklahoma. To the south of the trof, an axis of richer deep layer moisture resides over Oklahoma and northwest Arkansas. For the past couple of mornings, a persistent band of mid level clouds and thunderstorms have affected portions of northeast Oklahoma to the south and east of this feature. The activity today was displaced southeast of where it was yesterday, and the corresponding band of afternoon convection near the differential heating zone has also shifted southeast today compared to yesterday. The latest CAM guidance suggests that this band of mid level showers and storms will develop a bit farther southeast again tonight into Monday and have thus adjusted PoPs to account for this trend. The guidance suggests scattered afternoon convection could develop across the region on Monday afternoon. Afternoon heat indices will flirt with advisory criteria again, however, uncertainties regarding both the mid level cloud canopy and convection, and expected afternoon storm coverage could limit the spatial and temporal extent of the advisory heat. Therefore, will elect to hold off on any headlines and will let the next shift reevaluate. NW flow will develop aloft over the Plains as a strong shortwave trough dives southeast over the Great Lakes and Midwest. A weak surface front will drop down into the region, setting up for a favorable window for convective potential across portions of the region Monday night thru Wednesday. The heat should back off for a day or two as well. Mid level heights rise during the latter part of the week. The latest ECMWF shows a fairly intense low level thermal ridge extending east across Oklahoma Thursday and Friday ahead of a weak boundary. Our area could see widespread triple digit heat during this time frame. Temps may drop some for the weekend, but that isn`t completely certain this far out. The time period from mid July to mid August is our hottest time of year on average. Lacy && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...22
Area Forecast Discussion
National Weather Service Tucson AZ
240 PM MST Sun Jul 15 2018 .SYNOPSIS...Plenty of moisture and instability will remain in place to support daily showers and thunderstorms through the middle of this coming work week. A few storms may generate strong winds and heavy rain. With the storms, temperatures will generally remain below average. Drier air may spread into the region late in the week for less thunderstorm activity and warmer daytime temperatures. && .DISCUSSION...After a wet morning across much of southeast Arizona, the rain was ending with clouds diminishing in coverage late this afternoon. Showers and thunderstorms have struggled to redevelop in the Flash Flood Watch area northeast of Tucson. Latest HRRR solution suggested that the air mass was becoming too stable to support strong showers or thunderstorms this evening. However, regional radar continued to detect new thunderstorm development along the Rim country into the White Mountains. Despite what the HRRR was showing, will keep the Flash Flood Watch going for now based the possibility of the current activity moving into the watch area. Otherwise, the overall pattern will remain favorable for daily shower and thunderstorm activity. Medium ranges models still hinted at some drying and warming aloft by the end of this coming work week. If this materializes, less thunderstorm activity can be anticipated with high temperatures returning to seasonable readings. && .AVIATION...Valid through 17/06Z. Cloud bases from 5k-10k ft AGL with BKN-OVC clouds above 20k ft AGL. Isolated -TSRA/-SHRA, becoming scattered -TSRA/-SHRA after 16/21Z. Surface winds remain below 12 kts through the period. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Deep moisture continues to reside over the region allowing for the development of showers and thunderstorms. The pattern begins to gradually shift by the middle of next week reducing the probability of precipitation, but isolated storms could still develop, especially over the higher terrain. Temperatures also look to warm several degrees above normal. 20-ft winds remain below 15 mph, although the Upper Gila River Valley will experience gustier northwesterly winds at times. && .TWC WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 8 PM MST this evening for AZZ505-506- 509>511. && $$ Visit us on Facebook...Twitter...YouTube...and at